Before Harry could speak,

Before Harry could speak, there was a massive movement. The Gryffindors in front of him had risen and stood facing, not Harry, but the Slytherins. Then the Hufflepuffs stood, and almost at the same moment, the Ravenclaws, all of them with their backs to Harry, all of them looking toward Pansy instead, and Harry, awestruck and overwhelmed, saw wands emerging everywhere, pulled from beneath cloaks and from under sleeves.

“Thank you, Miss Parkinson.” said Professor McGonagall in a clipped voice. “You will leave the Hall first with Mr. Filch. If the rest of your House could follow.”

Harry heard the grinding of the benches and then the sound of the Slytherins trooping out on the other side of the Hall.

“Ravenclaws, follow on!” cried Professor McGonagall.

Slowly the four tables emptied. The Slytherin table was completely deserted, but a number of older Ravenclaws remained seated while their fellows filed out; even more Hufflepuffs stayed behind, and half of Gryffindor remained in their seats, necessitating Professor McGonagall’s descent from the teachers’ platform to chivvy the underage on their way.

“Absolutely not, Creevey, go! And you, Peakes!”

Harry hurried over to the Weasleys, all sitting together at the Gryffindor table.

“Where are Ron and Hermione?”

“Haven’t you found -?” began Mr. Weasley, looking worried.

But he broke off as Kingsley had stepped forward on the raised platform to address those who had remained behind.

“We’ve only got half an half an hour until midnight, so we need to act fast. A battle plan has been agreed between the teachers of Hogwarts and the Order of the Phoenix. Professors Flitwick, Sprout and McGonagall are going to take groups of fighters up to the three highest towers – Ravenclaw, Astronomy, and Gryffindor – where they’ll have good overview, excellent positions from which to work spells. Meanwhile Remus” – he indicated Lupin – “Arthur” – he pointed toward Mr. Weasley, sitting at the Gryffindor table – “and I will take groups into the grounds. We’ll need somebody to organize defense of the entrances or the passageways into the school – ”

“Sounds like a job for us.” called Fred, indicating himself and George, and Kingsley nodded his approval.

“All right, leaders up here and we’ll divide up the troops!”

“Potter,” said Professor McGonagall, hurrying up to him, as students flooded the platform, jostling for position, receiving instructions, “Aren’t you supposed to be looking for something?”

“What? Oh,” said Harry, “oh yeah!”

He had almost forgotten about the Horcrux, almost forgotten that the battle was being fought so that he could search for it: The inexplicable absence of Ron and Hermione had momentarily driven every other thought from his mind.

“Then go, Potter, go!”

“Right – yeah – ”

He sensed eyes following him as he ran out of the Great Hall again, into the entrance hall still crowded with evacuating students. He allowed himself to be swept up the marble staircase with them, but at the top he hurried off along a deserted corridor. Fear and panic were clouding his thought processes. He tried to calm himself, to concentrate on finding the Horcrux, but his thoughts buzzed as frantically and fruitlessly as wasps trapped beneath a glass. Without Ron and Hermione to help him he could not seem to marshal his ideas. He slowed down, coming to a halt halfway along a passage, where he sat down on the plinth of a departed statue and pulled the Marauder’s Map out of the pouch around his neck. He could not see Ron’s of Hermione’s names anywhere on it, though the density of the crowd of dots now making its way to the Room of Requirement might, he thought, be concealing them. He put the map away, pressed his hands over his face, and closed his eyes, trying to concentrate.

Voldemort thought I’d go to Ravenclaw Tower.

There it was, a solid fact, the place to start. Voldemort had stationed Alecto Carrow in the Ravenclaw common room, and there could be only one explanation; Voldemort feared that Harry already knew his Horcrux was connected to that House.